RRT [1]} was introduced by LaValle in 1998 as a path planning algorithm. In 2018, Chiang [2]} introduced COLREG-RRT that generated paths for ASV in various collision situations and with different numbers of vessels and our work is closely related to this paper. COLREG-RRT generates different virtual obstacles in different types of collision scenarios and grows RRT trees while avoiding virtual obstacles. However, COLREG-RRT does not guarantee that generated paths will always follow rules of the road, does not explicitly handle overtaking situations, and there is no minimum distance constraint to ensure that vessels do not come dangerously close to each other.
